Elastic fluid turbine shaft and disk structure and the like



Patented May 9, 1939 UNITE TAiE ATENT OFFICE ELASTIC FLUID TURBINE SHAFTAND DISK STRUCTURE AND THE LIKE York Application April 23, 1937, SerialNo. 138,575

4 Claims.

The present invention relates to elastic iiuid turbine shafts and diskstructures and the like, that is, to arrangements comprising a rotatableshaft and a disk secured thereto as are used for example in elastic uidturbines having a bucket wheel rigidly secured to a rotatable shaft.More broadly my invention relates to arrangements comprising two machineelements rigidly secured together with one machine element surroundingand engaging the other.

One object of my invention is to provide an improved construction andarrangement of the type above specied. Another object of my invention isto provide an improved method of manufacturing such structures.

For a consideration of what I believe to be novel and my invention,attention is directed to the following description and the claimsappended thereto in connection with the accompanying drawing.

In the drawing, Fig. 1 illustrates a structure embodying my invention,and Fig. 2 is a sectional View along line 2-2 of Fig. 1.

The arrangement shown in the drawing comprises a turbine shaft I9 and adisk I I forming part of a bucket wheel secured to the shaft. The shaftIl) has a tapered portion I2 and a flange or ring I3 adjacent that endof the tapered portion I2 which has the larger diameter. In the presentinstance the flange I3 and the tapered portion I2 are integrally formedwith the shaft II). The disk II has a bore or opening or recess Illwhich is tapered to t the tapered shaft portion I 2. A plurality oftapered bores I5 are formed in adjacent portions of the tapered shaftportion and the disk II. The bores I5 are tapered in a directionopposite to that of the taper of the shaft portion I2. In the presentinstance the shaft portion I2 is tapered towards` the left and the boresI5 are tapered towards the right. A tapered pin IB with a screw-threadedend portion I1 is disposed in each bore I5. The screwthreaded endportion I'I projects through an opening I 8 in the flange I 3. A nut I9bearing against the right-hand face of the flange I3 engages thescrew-threaded portion I 'I of the tapered pins I6 and thereby forcesthe disk I I into tight engagement with the tapered shaft portion I2.

When assembled, the right-hand face of the disk II is slightly spacedfrom the left-hand face of the iange I3 asrindicated at 29. This isimportant, especially in the case of elastic fluid turbines where thedisk is subject to considerable strains and stresses during operationwhich after a while cause certain deformations, resulting in looseningof the disk on the shaft. With the aforementioned spacing 2|] the diskII may be retightened on the turbine shaft, that is, drawn or forcedinto tight engagement with the tapered shaft portion I2 by tighteningthe nuts I9.

During manufacture the tapered bores I5 for the tapered pins I6 are madeafter the disk Il has been assembled with the tapered shaft portion I2.Upon finishing of the bores I5 the disk II is removed from the shaft tobe heated and thereupon shrunk o-nto the tapered shaft portion I2 andrigidly assembled therewith by inserting the tapered pins I6 andtightening the nuts I9 thereon.

With my invention I have accomplished animproved construction and methodof making and assembling structures comprising a shaft or first machineelement and a disk or second machine element. One of the elements has atapered portion engaging a tapered opening in the other element andrigidly secured to such other element by means of a plurality ofcircumferentially spaced tapered pins disposed in tapered openingsformed in adjacent portions of the two elements. 'Ihe tapered pins aresecured to a ring or like member bearing against or integrally formedwith the wider end of the tapered portion of said elements. In apreferred embodiment I provide at least three circumferentiallyuniformly spaced pins to maintain concentricity between the shaft andthe disk in case the latter should become loose during the operation.

Having described the method of operation of my invention, together withthe apparatus which I now consider to represent the best embodimentthereof, I desire to have it understood that the apparatus shown is onlyillustrative and that the invention may be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is,-

1. Elastic fluid turbine including the combinatio-n of a shaft having atapered portion, a flange formed at the wider end of the taperedportion, a bucket wheel disk with a tapered recess shrunk onto thetapered portion, at least three circumferentially spaced tapered boresformed in adjacent portions of the tapered shaft portion and the bucketwheel disk, the direction of the taper of the bores being opposite tothat of the taper of the recess, and a tapered pin disposed in each boreand having a screw-threaded portion secured to the ange.

2. Elastic fluid turbine including the combination of a shaft having atapered portion, a ring at the wider end of the tapered portion, abucket wheel disk with a tapered recess shrunk onto the tapered shaftportion, a plurality of tapered bores being formed in adjacent portionsof the shaft and the disk, and a tapered pin disposed in each bore andsecured to the ring, the adjacent surfaces of the disk and the ringbeing initially spaced to permit retightening of the disk on the taperedshaft portion after deformation of the disk during operation.

3. The combination of a rst machine element having a tapered portion, asecond machine element having a tapered opening surrounding and shrunkonto said tapered portion, and means rigidly securing the two elementstogether comprising at least three tapered pins disposed insubstantially uniformly spaced openings formed in adjacent portions ofthe two elements, the openings for the pins being tapered in a directionopposite to the taper of the tapered portion of the rst element.

4. Shaft and disk structure comprising a shaft having a tapered portionwith a flange having a plurality of circumferentially spaced bores atthe larger end of the tapered portion with a disk having a taperedopening engaging the tapered shaft portion with adjacent faces of thedisk and the flange slightly spaced, a plurality of circumferentiallyspaced bores formed in adjacent portions of the tapered portion and thedisk in alignment with the bores in the flange, the taper of said boresbeing opposite to that of the tapered shaft portion, a tapered pin ineach bore with a screw-threaded end portion projecting through the borein the ange, and a nut on said screw-threaded end portion to force thedisk onto the tapered shaft portion to maintain rigid connection betweenthe shaft and the disk.

DONALD F. WARNER.

